Plasmon-Enhanced Electrochemiluminescence for Nucleic Acid Detection Based on Gold Nanodendrites

Abstract

Gold nanodendrites (Au NDs) exhibit extremely strong electromagnetic field located around multiple tip branches due to a plasmon coupling effect. In this work, a novel LSPR-enhanced ECL emission from CdTe nanocrystals (NCs) by Au NDs for the detection of nucleic acid is reported. This system is composed of a thin film of CdTe NCs on glassy carbon electrode (GCE) as anodic ECL emitter and Au NDs as plasmon enhancer. DNA tetrahedron embedded with a stem-loop hairpin structure on one edge was applied as a switch to regulate the distance between CdTe NCs and Au NDs. At original state, the hairpin structure was closed and DNA tetrahedron played in a relaxed state on CdTe NCs film. The ECL emission of CdTe NCs was quenched by proximal Au NDs due to Förster resonance energy transfer (FRET), which was defined as the "turn-off" mode. After the complementary hybridization with target DNA, the hairpin structure changed to a rodlike configuration, resulting in an increased distance between CdTe NCs and Au NDs, and a significant enhancement of ECL induced by LSPR of Au NDs, which was defined as a "turn-on" mode. Along with the asymmetric modification method, a controllable and versatile pathway for modifying nanomaterials, the ECL sensor performed well with great stability and repeatability for nucleic acid detection in the range from 1.0 to 500 fM. Considering the high sensitivity and selectivity in the serum sample assay, this proposed method indicates a great potential for bioassay application.

An Electrochemiluminescence Biosensor for the Detection of Alzheimer’s Tau Protein Based on Gold Nanostar Decorated Carbon Nitride Nanosheets

“…In addition, AuNSs show a strong LSPR effect concentrated around the tips of branches which remarkably amplified the ECL intensity by producing more charge carriers. This enhancement mechanism has been reported in the literature [28,29]. (a) ECL intensity-time curves of GCE/pristine g-CN nanosheet (blue curve) system, GCE/AuNP@g-CN nanostructure system (red curve) and GCE/AuNS@g-CN nanostructure sys (green curve), and (b) ECL intensity-time curves of GCE/AuNS@g-CN system (red cur GCE/AuNS@g-CN/anti-Tau system (blue curve), GCE/AuNS@g-CN/ anti-Tau/BSA system (gr curve), GCE/AuNS@g-CN/anti-Tau/BSA/Tau protein system (Tau protein: 0.5 ng mL −1 , pur curve) and AuNS@g-CN/BSA/Tau protein system (Tau protein: 1 ng mL −1 , yellow curve).…”

Nanoengineered Metasurface Immunosensor with over 1000-Fold Electrochemiluminescence Enhancement for Ultra-sensitive Bioassay

“…When AuNPs approach to Ru(bpy) 3 2+ closely, non-radiative energy transfer plays an important role and then the ECL intensity enhancement is very limited. With the increase of SiO 2 shell thickness, energy transfer between the Ru(bpy) 3 2+ and AuNPs decrease rapidly, thus non-radiative energy transfer can be effectively prevented and the radiative mode dominates, resulting in significant ECL enhancement (Li et al., 2018). However, further increase in the thickness of SiO 2 shell will cause an exponential decay of the EM field with distance, which in turn decreases the ECL intensity.…”

“…Since the first report on surface plasmon-coupled ECL in 2004 (Zhang et al., 2004), Guo and Xu et al. have developed multiple strategies to fabricate SEECL systems based on the energy resonance transfer between Ru(bpy) 3 2+ and plasmonic nanoparticles (NPs), or between fluorescent quantum dot and plasmonic NPs, which greatly promoted the development of SEECL systems for ultrasensitive biodetections (Li et al., 2016, Li et al., 2018, Lu et al., 2018, Wang et al., 2011, Wang et al., 2015b).…”

A pH-engineering regenerative DNA tetrahedron ECL biosensor for the assay of SARS-CoV-2 RdRp gene based on CRISPR/Cas12a trans-activity

“…Electrochemiluminescence (ECL) immunoassay, the most advanced labeling immunoassay technique, is a new generation of labeling immunoassay technique after radioimmunoassay, enzyme immunoassay, fluorescence immunoassay and chemiluminescence immunoassay, which is sensitive, rapid and stable, and is the technological leader in solid-phase labeling immunoassay [25] , [26] , [27] . Electrochemiluminescence is a specific chemiluminescence reaction triggered by electrochemistry on the electrode surface, which is actually a perfect combination of two processes: electrochemistry and chemiluminescence [2] , [28] , [29] , [30] . The main difference between electrochemiluminescence and ordinary chemiluminescence is that the former is an electrically initiated luminescence reaction, cyclic and multiple luminescence, while the latter is a single instantaneous luminescence reaction initiated by a mixture of compounds [31] , [32] .…”